(noun) a true butthead; condition of having your head up your own ass, as if you are so stupid or self conceited that it seems you were born that way; a person who's head is up his/her own ass

A pick me is a woman that is willing to do anything for male approval. She will embarrass or throw other women under the bus to achieve this goal. The unfortunate thing about a pick me is usually the men they are trying to seek approval from are of poor quality and treat women badly, leaving little real benefit for the pick me.